メタデータ名 polygon
<http://xmlns.oracle.com/rdf/geo/srid/4612> POLYGON((131.3875000 31.6000000, 131.3937500 31.6000000, 131.3937500 31.6041667, 131.3875000 31.6041667, 131.3875000 31.6000000)) ^^http://www.opengis.net/ont/geosparql#wktLiteral